diff --git a/.swiftlint.yml b/.swiftlint.yml
index ef8311c1..eccf9282 100644
--- a/.swiftlint.yml
+++ b/.swiftlint.yml
@@ -39,6 +39,9 @@ only_rules:
   # Empty strings should be compared to `""` only if `isEmpty` cannot be used.
   - empty_string
 
+  # Prefer `flatMap { ... }` over `map { ... }.reduce([], +)`.
+  - flatmap_over_map_reduce
+
   # MARK comment should be in valid format.
   - mark